Abstract:

Blueberry leaves were extracted with 80% ethanol aqueous solution to prepare total flavonoids and the extract was analyzed qualitatively by means of color development reaction and UV-visible absorption spectroscopy. Meanwhile, its protecting effects against the lipid oxidation in lard and soybean lecithin liposomes prepared in our laboratory were investigated. The major components in the blueberry extract obtained were flavonoid compounds. The extract could effectively protect lard from lipid oxidation in a dose-dependent manner and presented the highest protecting effect at the dosage of 0.4%, which, however, was slightly lower than that of BHT. Synergistic protecting effects between ascorbic acid or citric acid and the extract were observed against the lipid oxidation in lard. In addition, the extract also presented an obvious protecting effect against the lipid peroxidation in soybean lecithin liposomes, which was higher than that of ascorbic acid. The IC50 values of the crude extract from blueberry leaves and its refined counterpart for the protection against lipid peroxidation were 67.46μg/mL and 121.65μg/mL, respectively. Total flavonoids derived from blueberry leaves are a potential natural antioxidant.

Key words: flavonoids from blueberry leaves, qualitative analysis, antioxidation, lard, liposome